WASHINGTON—President
Donald Trump
on Monday warned Rep. Maxine Waters to “be careful what you wish for,” two days after the California congresswoman urged supporters to harass members of the Trump administration in public places.

Referring to Ms. Waters as an “extraordinarily low IQ person,” Mr. Trump tweeted Monday: “She has just called for harm to supporters, of which there are many, of the Make America Great Again movement.” He added: “Be careful what you wish for Max!”

At an event in Los Angeles Saturday, Ms. Waters sought to rally the crowd against Trump administration officials. “If you see anybody from that cabinet in a restaurant, in a department store, at a gasoline station, you get out and you create a crowd,” she said. “And you push back on them. And you tell them they’re not welcome anymore, anywhere.”

On Friday night, White House press secretary
Sarah Sanders
was asked by the owner of the Red Hen restaurant in Lexington, Va., to leave. Tweeting about the incident Saturday, Ms. Sanders said she was asked to leave “because I work for @POTUS” and that she “politely left.”

“Her actions say far more about her than about me,” she added. “I always do my best to treat people, including those I disagree with, respectfully and will continue to do so.” She also addressed the matter at Monday’s press briefing, saying: “We are allowed to disagree, but we should be able to do so freely and without fear of harm.”

Mr. Trump defended his press secretary on Monday, calling her a “fine person.”

Last week, protesters chanted “Shame!” at Homeland Security Secretary
Kirstjen Nielsen
while she was dining at a Mexican restaurant, hours after she defended the White House’s zero-tolerance policy that resulted in the separation of thousands of immigrant children from their families at a briefing with reporters.

Mr. Trump has drawn criticism in the past for
Twitter
statements making threats about rivals. During the primaries, he threatened to “spill the beans” on another candidate’s wife, and said the billionaire Ricketts family had a “lot to hide,” without ever providing any evidence for either assertion. He was also denounced for making remarks at campaign rallies where he backed rougher treatment of protesters by security and supporters—saying of one protester, “I’d like to punch him in the face”—which critics saw as creating a dangerous atmosphere and encouraging violence.

Ms. Waters’s comments over the weekend spurred criticism from members of her own party. Senate Minority Leader
Chuck Schumer
(D., N.Y.) said Monday: “No one should call for harassment of political opponents. That’s not right. That’s not American.”

House Minority Leader
Nancy Pelosi
(D., Calif.) tweeted a link to Ms. Waters’s comments and wrote: “Trump’s daily lack of civility has provoked responses that are predictable but unacceptable. As we go forward, we must conduct elections in a way that achieves unity from sea to shining sea.”